DALLAS — Muhammad Ali’s 1974 Rumble in the Jungle championship belt fetched an impressive $6.18 million at a Dallas auction on Sunday.

The winner of the auction was owner and CEO of the Indianapolis Colts Jim Irsay. Irsay tweeted that the iconic belt has been added his collection of rock music memorabilia and American history and pop culture artifacts, just in time for his August and September show.

The green leather belt, sporting gold-colored metal in the center, was awarded to Ali after his iconic victory over George Foreman in 1974. Ali knocked out Foreman in eighth round of a fight in Kinshaza, Zaire, in October 1974. Ali claimed the world heavyweight title for the second time.

There are only two Ali WBC belts known to exist. One is in a private museum collection, and the other one now belonging to Irsay.​

The most hyped professional fight of its day, The Rumble in the Jungle drew roughly 60,000 fans and has been called “arguably the greatest sporting event of the 20th century.” Ali came in a 4-1 underdog against the enormously strong and at the time undefeated Foreman.

It also marked the introduction of Ali’s rope-a-dope tactic, which allowed him to wear the stronger Foreman down.

The televised event was watched by an estimated 1 billion people around the world, making it the most-watched live television broadcast of all time. The fight grossed in the neighborhood of $100 million.